20 MAINE AGRICULTURAL EXPERIMENT STATION. I909. 



tions. As a possible suggestion let us again refer to the weather 

 records. We find a snow storm complicating matters just at 

 the time of the thaw between the two low temperature records 

 of the season. See Fig. 3, p. 15. On January 19 the maxi- 

 mum thermometer read -j-20° F. and dropped off to only 2° 

 F. toward night, when the weather changed and by 2 P. M. the 

 next day the temperature was +45° F. Four inches of snow 

 fell in the afternoon and night of the 19th, but with the rising 

 temperature this was probably of such a consistency as to load 

 up and adhere to the trees particularly in the crotches. The 

 storm stopped before morning, ending with a trace of rain but 

 not enough to dispose of the snow. The thermometer dropped 

 to -f-io on the night of the 20th following the record of +45° F- 

 On the day following it rose again to +47° F. only to fall f : 

 degrees F. during the night to — 13° F. It seems then that the 

 loading up of the trees with soft snow which later thawed 

 some and suddenl}^ froze again two days in succession, the 

 second a very severe drop in temperature, gives conditions 

 which may account for the crotch injury. The crotches would 

 be filled with greater or less deposits of ice which radiated heat 

 with more rapidity than the parts of the trunk not so covered 

 and caused the injury described. 



Correspondence with Prof. W. T. Macoun of the Central 

 Experimental Farms, Ottawa, showed that he had observed the 

 same trouble in various parts of the adjoining Provinces of 

 Canada coincident with its occurrence in Maine. Without 

 knowing that the crotch injury was being studied by the other 

 both Prof. Macoun and the writer arrived at practically the 

 same conclusion as to the cause, as will be seen from the follow- 

 ing quotations kindly furnished by Professor Macoun from the 

 forthcoming report of his Department for the year 1907. 



"Crotch Injury. — The effects of crotch injury have been very 

 serious in the Province of Quebec and in some parts of Ontario 

 in recent years. On examination it is found that in the center 

 of the crotch and on the branches diverging from it, but close 

 to it, the bark is dead. As a result of this killing in the crotch 

 the tree loses its strength there, rot sets in and eventually the 

 tree is destroyed by the loss of one limb after another at the 

 •crotch. This crotch injury is probably due to ice lodging in the 



